U.S. patent number 6,884,968 [Application Number 10/692,728] was granted by the patent office on 2005-04-26 for apparatus and process for annealing a multilayer body, and multilayer body of this type.
This patent grant is currently assigned to Shell Solar GmbH. Invention is credited to Volker Probst.
United States Patent |
6,884,968 |
Probst |
April 26, 2005 |
Apparatus and process for annealing a multilayer body, and
multilayer body of this type
Abstract
A process for annealing large-area multilayer bodies by
supplying a quantity of energy at an annealing rate of at least
1.degree. C./s. To suppress temperature inhomogeneities during the
annealing, different partial quantities of the quantity of energy
are supplied to the layers of the multilayer body with a local and
temporal resolution. The multilayer body is annealed in a container
which has a base and a cover made from glass-ceramic. The process
is used to produce a thin-film solar module.
Inventors: |
Probst; Volker (Munich,
DE) |
Assignee: |
Shell Solar GmbH (Munich,
DE)
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Family
ID: |
7916741 |
Appl.
No.: |
10/692,728 |
Filed: |
October 27, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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048419 |
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6717112 |
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Foreign Application Priority Data
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Jul 30, 1999 [DE] |
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199 36 081 |
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Current U.S.
Class: |
219/390;
118/50.1; 118/724; 118/725; 219/411; 392/418; 392/416; 219/405 |
Current CPC
Class: |
B32B
38/0036 (20130101); H01L 31/0749 (20130101); H01L
31/18 (20130101); H01L 31/032 (20130101); B32B
2310/0806 (20130101); Y02E 10/541 (20130101) |
Current International
Class: |
H01L
31/18 (20060101); F27B 005/14 () |
Field of
Search: |
;219/390,405,411
;392/416,418 ;118/724,725,501 |
References Cited
[Referenced By]
U.S. Patent Documents
|
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4976996 |
December 1990 |
Monokowski et al. |
5314538 |
May 1994 |
Maeda et al. |
5443646 |
August 1995 |
Yamada et al. |
5578503 |
November 1996 |
Karg et al. |
5614133 |
March 1997 |
Tanaka et al. |
5861609 |
January 1999 |
Kaltenbrunner et al. |
5926742 |
July 1999 |
Thakur et al. |
6173116 |
January 2001 |
Roozeboom et al. |
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Foreign Patent Documents
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195 44 525 |
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Jun 1996 |
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DE |
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197 11 702 |
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Jun 1998 |
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DE |
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0 399 662 |
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Nov 1990 |
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EP |
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0 662 247 |
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Mar 1999 |
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EP |
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0 926 719 |
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Jun 1999 |
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EP |
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57-183041 |
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Nov 1982 |
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JP |
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07078830 |
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Mar 1995 |
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JP |
|
Other References
Takayuki Watanabe et al., "Solar Cells Based on CulnS.sub.2 Thin
Films through Sulfurization of Precursors Prepared by Reactive
Sputtering with H.sub.2 S Gas," Jpn. J. Appl. Phys., V. 35, 1996,
pp. 1681-1684. .
F. Karg et al., "Novel Rapid-Thermal-Processing for CIS Thin-Film
Solar Cells," IEEE, 1993, pp. 441-446. .
J. Ermer et al., "Advances in Large Area CulnSe.sub.2 Thin Film
Modules," IEEE, 1990, pp. 595-599. .
E. Niemi et al., "Small-and Large-Area CIGS Modules by
Co-Evaporation," IEEE, 25.sup.th PVSC, 1996, pp. 801-804. .
Nowshad Amin et al., "New Approaches on Thinner CdTe Thin-Film
Solar Cells," Thin Film Cells and Technologies, 2.sup.nd World
Conference on Photovoltaic Solar Energy Conversion, 1998, pp.
1081-1084..
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Primary Examiner: Fuqua; Shawntina
Attorney, Agent or Firm: Young & Thompson
Parent Case Text
This application is a Divisional of U.S. patent application Ser.
No. 10/048,419 filed on May 9, 2002 now U.S. Pat. No. 6,717,112.
Application Ser. No. 10/048,419 is the national phase of PCT
International Application No. PCT/DE00/02523 filed on Jul. 31, 2000
under 35 U.S.C. .sctn. 371. The entire contents of each of the
above-identified applications are hereby incorporated by reference.
Claims
What is claimed is:
1. A process for annealing a multilayer body which has a first
layer and at least one second layer, wherein during annealing, a
quantity of energy is taken up by the multilayer body such that a
first quantity of the quantity of energy is taken up by the first
layer and a second quantity of the quantity of energy is taken up
by the at least one second layer, wherein at least one second layer
has a defined absorption for a defined electromagnetic radiation,
comprising the following process steps: a) providing an apparatus
for annealing a multilayer body, which apparatus comprises an
energy source comprising a first energy source and at least one
second energy source emitting the defined electromagnetic
radiation, and a transparency body that is semi-transparent and has
a defined transmission and a defined absorption with respect to the
defined electromagnetic radiation; b) arranging the multilayer body
between the first energy source and the at least one second energy
source, so that the first layer is arranged between the first
energy source and the at least one second layer, and the at least
one second layer is arranged between the second energy source and
the first layer and that the transparency body is positioned
between the at least one second energy source and the at least one
second layer; and c) annealing the multilayer body using the energy
source to supply the quantity of energy to the multilayer body.
2. The process as claimed in claim 1, in which at least one
material of one of the layers of the multilayer body is selected
from the group consisting of glass, glass-ceramic, ceramic, plastic
and/or metal.
3. The process as claimed in claim 1, in which, for annealing, the
transparency body absorbs a defined quantity of energy, and the
quantity of energy is supplied to the layer by heat conduction
and/or heat radiation.
4. The process as claimed in claim 1, in which, during the
annealing, a measurement, which is dependent on the annealing, of a
physical parameter of the apparatus is detected in order for the
uptake of the quantity of energy during the annealing to be
controlled, and the quantity of energy is controlled.
5. The process as claimed in claim 1, in which at least one layer
is brought into contact with a process gas.
6. The process as claimed in claim 1, which is carried out as a
process stage in an in-line process and/or a quasi-inline process
comprising at least two process stages.
7. The process as claimed in claim 1, in which a multilayer body is
produced, comprising a first layer of at least one substance which
is selected from the group consisting of copper, indium, gallium,
sulfur and/or selenium, and a second layer comprising glass, a
lateral diameter of the multilayer body being selected from the
range between 0.3 m and 5 m.
8. The process according to claim 7, wherein the multilayer body
has a lateral diameter in the range between 1.0 m and 5 m.
9. The process as claimed in claim 2, in which, for annealing, the
transparency body absorbs a defined quantity of energy, and the
quantity of energy is supplied to the layer by heat conduction
and/or heat radiation.
10. The process as claimed in claim 2, in which, during the
annealing, a measurement, which is dependent on the annealing, of a
physical parameter of the apparatus is detected in order for the
uptake of the quantity of energy during the annealing to be
controlled, and the quantity of energy is controlled.
11. The process as claimed in claim 3, in which, during the
annealing, a measurement, which is dependent on the annealing, of a
physical parameter of the apparatus is detected in order for the
uptake of the quantity of energy during the annealing to be
controlled, and the quantity of energy is controlled.
12. The process as claimed in claim 2, in which at least one layer
is brought into contact with a process gas.
13. The process as claimed in claim 2, which is carried out as a
process stage in an in-line process and/or a quasi-in-line process
comprising at least two process stages.
14. The process as claimed in claim 2, in which a multilayer body
is produced, comprising a first layer of at least one substance
which is selected from the group consisting of copper, indium,
gallium, sulfur and/or selenium, and a second layer comprising
glass, a lateral diameter of the multilayer body being selected
from the range between 0.3 m and 5 m.
Description
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for annealing a multilayer
body, which has a first layer and at least one second layer,
through uptake of a quantity of energy by the multilayer body
involving uptake of a first partial quantity of the quantity of
energy by the first layer and uptake of a second partial quantity
of the quantity of energy by the second layer, having at least one
energy source. An apparatus of this type is known, for example,
from EP 0 662 247 B1. As well as the apparatus, the invention also
proposes a process for annealing a multilayer body and a multilayer
body of this type.
A multilayer body is produced, for example, by applying a
functional layer to a substrate layer. To ensure that the
functional layer and/or the substrate layer has a desired physical
(electrical, mechanical, etc.) and/or chemical property, under
certain circumstances it is necessary for the multilayer body or
the layer and/or the substrate layer to be processed. The
processing comprises, for example, annealing of the multilayer body
in the presence of a gas (process gas).
A multilayer body is, for example, a large-area thin-film solar
cell, in which an electrode layer comprising molybdenum and a
functional copper-indium-diselenide (CIS) semiconductor layer are
applied to a substrate layer of glass. This thin-film solar cell is
produced in a two-stage process according to EP 0 662 247 B1. In a
first stage, the following elements are applied in layer form, in
order, to the glass substrate layer:molybdenum, copper, indium and
selenium. In a second stage, the multilayer body obtained in this
way is annealed, leading to the formation of the copper-indium
diselenide semiconductor layer.
For annealing, the multilayer-body is arranged in a closed
container made from graphite. During the annealing, a defined
partial pressure of gaseous selenium is formed in the interior of
the container, the layers which have been applied to the glass
being brought into contact with the gaseous selenium.
During the annealing, the multilayer body takes up a quantity of
energy, each layer being supplied with a partial quantity of the
quantity of energy. The annealing takes place, for example, at a
heat-up rate of 10.degree. C./s. The energy source for the quantity
of energy which is used is a halogen lamp. The halogen lamp is used
to irradiate the graphite container and thus to heat the container.
An operation of this type is particularly efficient, since graphite
which acts, as it were, as a "black body radiator", has a high
absorption capacity for electromagnetic radiation, in particular
for radiation in the spectral region of the halogen lamp. The
quantity of energy absorbed by the graphite is fed to the
multilayer body by heat radiation and/or heat conduction. The
container therefore functions as a secondary energy source or as an
energy transmitter.
Graphite has a high emission capacity and a high thermal
conductivity. When the multilayer body is resting on a base of the
container, the quantity of energy is supplied to an underside of
the multilayer body substantially by heat conduction. A quantity of
energy is fed to an upper side of the multilayer body by heat
radiation.
On account of an asymmetric layer structure of the multilayer body
and/or a different quantity of energy being supplied to the top
side and the underside of the multilayer body, a high heating rate
may lead to inhomogeneous, i.e. non-uniform annealing of the layers
of the multilayer body. Temperature inhomogeneity may form in the
thickness direction of the multilayer body and, given a coefficient
of thermal expansion of a material of a layer which is not zero,
may lead to mechanical stress within the layer and/or the
multilayer body. This mechanical stress may cause the layer and/or
the multilayer body to crack or fracture. The mechanical stress may
also lead to deformation (distortion) of the multilayer body. In
the case of a substrate layer made from glass, the deformation is
generally transient, i.e. disappears again after the annealing. The
deformation may also be permanent. In this case, the deformation
does not disappear again. This is the case if a softening point of
the substrate layer (e.g. of glass) is exceeded during the
annealing and an (internal) mechanical stress and/or an external
force becomes active.
The larger the area of the multilayer body and the higher the
annealing rate (heating rate, cooling rate), the more difficult it
becomes to deliberately influence temperature inhomogeneities in
the multilayer body during the annealing of the multilayer body and
the greater the likelihood of an undesirable mechanical stress
occurring.
It is an object of the invention to demonstrate how temperature
homogeneity or temperature inhomogeneity can be deliberately
influenced during the annealing of a large-area multilayer body
with a high annealing rate.
SUMMARY OF THE INVENTION
To achieve the object, the invention proposes an apparatus for
annealing a multilayer body, which has a first layer and at least
one second layer, through uptake of a quantity of energy by the
multilayer body involving uptake of a first partial quantity of the
quantity of energy by the first layer and uptake of a second
partial quantity of the quantity of energy by the second layer,
having at least one energy source for the quantity of energy. The
apparatus is characterized in that a first energy source and at
least one second energy source are present, at least one of the
energy sources emits a defined electromagnetic radiation with a
radiation field, at least one of the layers has a defined
absorption for the electromagnetic radiation, the first layer can
be arranged between the first energy source and the second layer,
and the second layer can be arranged between the second energy
source and the first layer, in such a manner that the layer which
absorbs the electromagnetic radiation is situated in the radiation
field, and at least one transparency body, which has a defined
transmission and a defined absorption with respect to the
electromagnetic radiation is arranged in the radiation field
between the energy source with the radiation field and the layer
which absorbs the electromagnetic radiation.
The idea of the invention consists in individually heating the
layers of the multilayer body, i.e. of deliberately controlling,
regulating and/or presetting the partial quantity of the quantity
of energy which is taken up by a layer. By way of example, a
quantity of energy is determined with the aid of a control circuit
during the annealing (see below). It is also conceivable for the
energy sources to be preset (e.g. energy density, nature of the
energy, etc.), without the need for an additional control circuit.
The invention allows individual heating of the layers of the
multilayer body even at very high heating rates of 1.degree. C./s
up to, for example, 50.degree. C./s and above. The individual
heating makes it possible to minimize mechanical stress and
deformation of the multilayer body which may result under certain
circumstances during the annealing.
The basis for this is the transparency body, which is optically
semitransparent. The transmission, which lies, for example, at a
defined wavelength between 0.1 and 0.9, causes the electromagnetic
radiation described above to pass through the transparency body
onto a layer. The layer can take up a corresponding quantity of
energy or partial quantity of the quantity of energy which is
emitted directly from the energy source.
However, the transparency body also has a certain absorption for
the electromagnetic radiation. The energy which is thereby taken up
may be emitted to a surrounding area in the form of heat radiation
and/or heat conduction. In a particular configuration, the
apparatus for annealing a multilayer body has a transparency body
which radiates and/or conducts heat in the direction of the
multilayer body through the absorption of the electromagnetic
radiation. In this way, it is possible to anneal a layer by heat
radiation and/or heat conduction.
It is also conceivable for a first layer of the multilayer body,
which transmits the heat radiation, to be annealed substantially
only by the heat conduction, while a second layer of the same
multilayer body is annealed substantially by the heat radiation
from the same transparency body. A first layer which exhibits
corresponding transmission is, for example, a layer comprising
glass. If electromagnetic radiation from an energy source and/or a
transparency body comes into contact with the glass body, a small
proportion of the radiation (approximately 4%) is reflected. Most
of the radiation (>90%) passes through the glass more or less
without obstacle and then impinges on a second layer of the
multilayer body, where this radiation can be absorbed and can lead
to a quantity of energy being taken up by this second layer. The
glass layer cannot be annealed sufficiently quickly by radiation or
heat radiation at a very high heating rate. By contrast, relatively
quick annealing can be achieved by heat conduction if the
transparency body is able to take up a partial quantity of the
quantity of energy and transmit it to the glass layer.
The situation in which the transparency body itself is a layer of
the multilayer body is also conceivable. The transparency body can
take up a partial quantity of the quantity of energy through
absorption of part of the electromagnetic radiation and, by
transmission, can pass on a further partial quantity of the
quantity of energy in order for this partial quantity to be taken
up by a further layer.
In a particular configuration, a multilayer body in which one layer
functions as a substrate layer for at least one further layer is
used in the process. The multilayer body has in particular an
asymmetric layer sequence. By way of example, the multilayer body
comprises a substrate layer which is coated on one side. Individual
layers of the multilayer body may also be arranged next to one
another.
In a particular configuration, one layer of the multilayer body
ncludes a material which is selected from the group consisting of
glass, glass-ceramic, ceramic, metal and/or plastic. A suitable
plastic is in particular heat-resistant plastic, such as Teflon.
One layer is, for example, a metal foil. The metal foil may also
function as a substrate layer.
The partial quantity of the quantity of energy which is taken up by
a layer is dependent, for example, on an absorption, emission
and/or reflection property of the layer. However, it is also
dependent on the nature of the energy source and on the way in
which the quantity of energy is transmitted to the multilayer body
or to a layer of the multilayer body. The annealing of the
multilayer body or of a layer takes place, for example, with the
aid of an energy source for thermal energy. The layer may be
supplied with the thermal energy directly. Heat radiation, heat
conduction and/or convection are suitable means for achieving this.
In the case of heat radiation, the energy source itself may be a
source of heat radiation. The heat radiation is, for example,
electromagnetic radiation in the wavelength range between 0.7 and
4.5 .mu.m (infrared light). The corresponding layer is arranged in
the radiation field of the energy source. The electromagnetic
radiation from the energy source impinges on the layer, which at
least partially absorbs the electromagnetic radiation.
However, it is also possible for a layer to be supplied with any
desired energy, which is converted into thermal energy in the
layer. By way of example, a layer is irradiated with high-energy UV
light, which the layer absorbs. Absorption of a high-energy light
quantum causes a molecule of the layer or the entire layer to
become electronically excited. Energy which is taken up in the
process can be converted into thermal energy.
As well as heat radiation and heat conduction, it is also possible
for a layer or the entire body to be annealed through convection.
In this case, a gas with a defined energy is guided past the layer,
the gas releasing the energy to the layer. The gas which is guided
past may simultaneously function as process gas.
Moreover, a layer can also be cooled by heat conduction and/or
convection. In this case, negative thermal energy is supplied to
the layer. In this way, it is also possible to control the
quantities of energy or the partial quantities of the quantities of
energy and, for example, to additionally influence the
mechanical-stresses in the multilayer body.
In a particular configuration, there is an energy transmitter for
transmitting the quantity of energy to the multilayer body.
The energy transmitter functions as a secondary energy source. The
energy transmitter absorbs, by way of example, electromagnetic
radiation from a primary energy source, e.g. a halogen lamp, from a
higher energy area and converts this electromagnetic radiation into
heat radiation which is absorbed by the layer.
The indirect and/or direct vicinity of the multilayer body can
function as energy transmitter during the annealing. It is
conceivable for an energy transmitter to be arranged with the
multilayer body which is to be annealed in an interior space of a
container. The energy transmitter may also be arranged outside the
container, for example on a wall of the container or at a distance
from the container. It is conceivable for the energy transmitter to
be a coating of the container. By way of example, the energy
transmitter may be a graphite film. It is even possible for the
container itself to act as an energy transmitter. A function of
this type is provided, for example, in the case of a container made
from graphite. Finally, the transparency body is nothing other than
an energy transmitter. Likewise, a gas, when transmitting energy
through convection, acts as an energy transmitter.
A quantity of energy which is taken up by the multilayer body may
differ not only from layer to layer but also within a layer. By way
of example, during the annealing an edge effect occurs in the
multilayer body or in a layer of a multilayer body. An edge region
of the layer is at a different temperature from an inner region of
the layer. During the annealing, a lateral temperature gradient is
established. This takes place, for example, if a radiation field of
the energy source is inhomogeneous. In this case, an energy density
of the radiation field over a surface through which the radiation
is radiated is not identical everywhere. Lateral temperature
inhomogeneity may also be established when the radiation field is
homogeneous, if a greater quantity of energy per unit volume is
absorbed at the edge of a layer, on account of the larger absorbing
area per unit volume. To compensate for the temperature gradient,
it is possible, for example, to use an energy source which
comprises a multiplicity of subunits. Each subunit may be actuated
separately, and in this way each quantity of energy supplied from a
subunit to a layer can be set separately. An example of an energy
source of this type is an array or matrix of individual heater
elements. An example of a heater element is a halogen lamp. The
array or matrix can also be used to produce a lateral temperature
gradient in the layer. In this way, it would be possible, for
example, to deliberately produce permanent or transient deformation
of the layer body. An array or matrix is highly advantageous in
particular for the annealing of a multilayer body in which layers
lie next to one another.
In connection with the energy source, it is advantageous if the
energy source or sources operate continuously. However, it is also
conceivable for the energy sources to make the quantity of energy
or the partial quantities of the quantity of energy available to
the layers in a cyclical or pulsed mode. An energy source of this
type is, for example, an energy source with pulsed electromagnetic
radiation. In this way, a quantity of energy can be supplied to the
layers at the same time or in a temporal sequence (e.g.
alternately).
The following properties of the energy source for electromagnetic
radiation are particularly advantageous: The energy source has a
homogeneous radiation field. A spectral intensity distribution of
the energy source partially overlaps a spectral absorption of the
layer, of the transparency body and of any container which may be
present (cf. below). In the presence of a process gas, the energy
source is resistant to and/or protected from corrosion. The energy
source has a high energy density, which is sufficient to enable a
mass of the multilayer body (and if appropriate that of a
container) to be heated with a heating rate of over 1.degree.
C./s.
In a particular configuration, the transparency body of the
apparatus has at least one spacer, onto which the multilayer body
can be placed in order for a laterally homogeneous quantity of
energy to be taken up by the multilayer body. By way of example,
the layer by means of which the multilayer body rests on the
transparency body or the spacer is annealed primarily by
homogeneous thermal radiation. In this form, the spacer preferably
includes a material which has a low level of absorption for the
electromagnetic radiation. A spacer projects beyond a surface of
the transparency body, for example by a few .mu.m to mm.
The layer resting on the spacers may also be annealed primarily
through heat conduction. For this purpose, the spacers have, for
example, a thermal conductivity which is required in order to
achieve the corresponding annealing rate. It is also conceivable
for the spacer, in order to transmit energy by heat conduction, to
have a high absorption in respect of electromagnetic radiation from
an energy source, the electromagnetic radiation being efficiently
converted into thermal energy.
In particular, the transparency body has a multiplicity of spacers
of this type. With a multiplicity of spacers which are arranged
evenly, in contact, between the layer of the multilayer body and
the transparency body, it is additionally possible to achieve
homogenization of the lateral temperature distribution.
In a particular configuration, the transparency body and/or the
spacer includes a material which is selected from the group
consisting of glass and/or glass-ceramic. Glass-ceramic has various
advantages: It can be used for annealing within a wide temperature
range from, for example, 0.degree. C. to, for example, 700.degree.
C. Glass-ceramic has, by way of example, a softening point which
lies above the temperature range. It has a very low coefficient of
thermal expansion. It is able to withstand thermal shocks and is
free of distortion within the abovementioned temperature range for
the annealing. It is chemically inert with respect to a wide range
of chemicals and is relatively impermeable to these chemicals. A
chemical of this type is, for example, the process gas to which a
layer and/or the entire multilayer body is exposed during the
annealing. It is optically semitransparent in the spectral region
of numerous energy sources for electromagnetic radiation, in
particular in a wavelength region in which a radiation density from
the energy sources is high. A radiation source of this type is, for
example, a halogen lamp with a high radiation density between 0.1
and 4.5 .mu.m.
Glass, in particular quartz glass, are also conceivable for use as
materials for the transparency body. The advantage of glass is that
it can be used at high temperatures of up to 1200.degree. C. These
materials have a high transmission and low absorption in the
spectral region of an energy source in the form of a halogen lamp.
The light passes through this transparency body substantially
without obstacle and passes to a layer with a corresponding
absorption for the electromagnetic radiation, the layer taking up a
quantity of energy and being heated. The transparency body is
scarcely heated by the radiation.
In one process application, it is possible for material of the
heated layer to be evaporated and deposited on a relatively cold
surface of the transparency body. To prevent this, it is possible
to ensure that the transparency body is heated to a required
temperature during the annealing. This is achieved by transferring
a quantity of energy to the transparency body by heat conduction
and/or convection. Electromagnetic radiation which the transparency
body absorbs is also conceivable. It is conceivable for the
transparency body to have a coating which absorbs a certain
proportion of the electromagnetic radiation. The energy which is
taken up as a result can be transmitted to the transparency body
made from glass or quartz glass. In this form, the transparency
body, comprising the glass body with the coating, is optically
semitransparent and can be used to transmit energy to the
multilayer body both by heat radiation and by heat conduction.
In a particular configuration of the invention, at least one layer
can be brought into contact with a process gas. It is also
conceivable for the entire multilayer body to be exposed to the
process gas. During the annealing, the process gas acts on the
layer or on individual layers or on the entire multilayer body and
is involved in the change in the physical and chemical properties
of the multilayer body. An example of a suitable process gas is an
inert gas (molecular nitrogen or noble gas). The process gas does
not react with a material of the layer. However, a process gas
which does react with a material of the layer is also conceivable.
The functional layer forms under the action of the process gas. By
way of example, the process gas has an oxidizing or reducing action
with respect to a material of the layer. Possible process gases for
this purpose are oxygen, chlorine, hydrogen, elemental selenium,
sulfur or a hydride. It may also be an etching process gas, such as
HCl or to like. Further examples of the process gas are H.sub.2 S
and H.sub.2 Se, which are used for the production of a thin-film
solar cell (cf. below). Finally, all gases or gas mixtures which
react with a material of a layer in a suitable way are
conceivable.
It is advantageous if the layer is exposed to a defined process-gas
atmosphere. The defined process-gas atmosphere comprises, for
example, a partial pressure of the process gas or gases during the
annealing. By way of example, it is also conceivable for a layer or
the multilayer body to be in contact with vacuum in order for
annealing to be carried out.
A defined process-gas atmosphere can be achieved, for example, by
guiding the process gas past the layer at a defined velocity.
During the annealing, a process gas with various partial pressures
can act on the layer. It is also conceivable for various process
gases to be in contact with the layer of the layer body in
succession.
Preferably, at least the layer which is in contact with the process
gas is enclosed. This is achieved, for example, by sheathing the
layer, it being possible for the sheathing to be secured to the
substrate layer. The sheathing is filled with the process gas
before or during the annealing. The process gas is in the process
concentrated on a surface of the layer whose properties are to be
influenced by the process gas. In this way, it is possible to
prevent a surrounding area from being contaminated by the process
gas. This is particularly important when using a corrosive and/or
toxic process gas. Moreover, it is possible to operate with a
stoichiometric quantity of process gas which is required for
conversion of the layer. There is no unnecessary consumption of
process gas.
In a particular configuration of the invention, there is a
container for holding the multilayer body during the annealing. The
transparency body is in particular a wall of the container. The
container has the advantage that it automatically forms the
sheathing of the layer or of the entire multilayer body. The
sheathing does not need to be secured to the multilayer body. In
the case of a closeable container, the process-gas atmosphere can
be set specifically and easily. In particular, for this purpose the
container has at least one gas opening for evacuation of the
container and/or filling of the container with the process gas. In
a particular embodiment, the gas opening is produced by an
automatically closeable valve. The process-gas atmosphere can be
set actively. The gas opening can also be used in order to fill the
container with any desired gas, for example a purge gas. The
process-gas atmosphere may also be set or adjusted during the
annealing.
To specifically set the process-gas atmosphere, however, it is also
possible for the container to have a sufficiently large volume for
the process gas required during the annealing. If the annealing
requires a homogeneous and reproducible distribution of the process
gas over a layer, it is also possible to specifically establish a
gas discharge from the container. This may be required, for
example, if annealing is carried out at a very high heating rate.
In this case, the process gas expands. If the container is unable
to withstand the gas pressure which occurs as a result, the
container will be deformed or even destroyed. However, deformation
should be prevented, for example, if the multilayer body is resting
on the base of the container. As described above, deformation of
the container leads to lateral temperature inhomogeneity in the
multilayer body, with the corresponding consequences.
Moreover, the container may be means for conveying the multilayer
body during the annealing. The container has the advantage that,
during the annealing, it is not possible, for example, to rule out
the possibility of a layer (substrate layer) of glass breaking. In
the event of a substrate of this type breaking, the broken material
can easily be removed from an installation for annealing the
multilayer body. This contributes to stabilizing the process in the
annealing installation.
In a particular configuration, the wall of the container which
includes the transparency body is a cover and/or a base of the
container. By way of example, one layer of the multilayer body
rests directly on the transparency body of the base. As described
above, the transparency body may have spacers. The cover likewise
includes the transparency body which, by way of example, is not in
contact with the multilayer body or a layer of the multilayer body.
In this way, the layer of the multilayer body which rests on the
base can be heated by heat conduction, and the layer which faces
the cover can be heated by heat radiation. The layer facing the
cover can easily be exposed to a process gas.
However, the cover of the container can also be characterized by
high absorption of the electromagnetic radiation which is emitted
by an energy source.
In a further configuration, the base and/or the cover of the
container is formed by in each case at least one multilayer body.
In this case, the layer of the multilayer body which, for example,
is to come into contact with a process gas is directed into an
interior of the container. This solution is possible if the
multilayer body or the layers of the multilayer body have a low
coefficient of thermal expansion and/or the annealing rate is low.
In the case of a high annealing rate, the multiplayer body
advantageously has a substrate layer with a high coefficient of
thermal conductivity. The substrate layer is directed outward. By
way of example, in this case the substrate layer is a transparency
body as described above.
With the container, the apparatus is suitable in particular for
carrying out the annealing in an in-line process with various
process stages which are carried out in different process
zones.
In the in-line process, the container can be conveyed either
continuously or discontinuously. In the case of the continuous
in-line process, the material being processed or the processing
container is moved through the processing installation throughout
the entire passage. The discontinuous or indexing mode of the
in-line process is characterized in that the processing box or the
material being processed is moving only during its transfer from
one process zone into the next, remaining in the process stage
until the sub-process has been concluded. In this case, it is
advantageous for the transfer time to be as short as possible when
compared to the residence time. The material or box is then
conveyed onward into the next process zone, followed by a further
residence time, etc. In the case of in-line installations which are
designed for indexing operation, it is advantageous for each
process zone to be at least of the size of a processing vessel, so
that the homogeneity of a process zone (for example the
temperature) can be transferred to the material being processed. In
a further configuration, all the processing zones which are fed by
indexing operation have the same dimensions, as seen in the
conveying direction. Consequently, simple conveyor mechanisms, such
as a conveyor chain, a conveyor belt or pusher conveying, can be
used to simultaneously load and unload, in indexing mode, not just
one process zone, but rather all adjacent process zones.
By way of example, the multilayer body is placed into the
container. The container is used to transport the multilayer body
from process stage to process stage or from process zone to process
zone. Each process stage, for example heating, cooling, evacuation
or filling of the container, can be carried out in a dedicated
process zone. In a first process stage, the container is filled
with, for example, a process gas. The container can be introduced
into a chamber which is provided specifically for that purpose,
where it can be evacuated, filled with a corresponding process gas
and closed. A separate inlet and outlet (gas opening) in the
container for purging or filling the container with the process gas
is possible. This gas opening can be connected to a coupling unit
and positioning unit in order for the processing box to be filled
with gas or evacuated. The coupling unit is used, for example, to
connect the container, in an in-line process, for example in
indexing mode, in order for a process stage to be carried out at a
specific location (process zone), to a corresponding unit (e.g.
vacuum pump, gas cylinder) in such a manner that the container can
be filled with the corresponding gas or emptied.
In a particular configuration, the container has a coupling unit
allowing the container to be arranged in a process zone. With the
aid of the coupling unit, it is possible to hold or position the
container in a process zone. For this purpose, by way of example,
the process zone likewise has a coupling unit. The coupling unit is
used, for example, to hold the container at a specific location
(process zone) in an in-line process for carrying out a process
stage and to connect it to a corresponding unit (e.g. vacuum pump,
gas cylinder), in such a manner that the container can be filled
with the corresponding gas or the container can be emptied. The
coupling unit of the container and the coupling unit of the process
zone function, for example, according to the key/hole
principle.
It is also conceivable for the container to be conveyed from
process zone to process zone with the aid of the coupling unit.
The following process sequence is conceivable: in a first process
stage, the container is filled, for example, with a process gas.
The container can be introduced into a chamber which is present
specifically for this purpose, where it can be evacuated, filled
with a corresponding process gas and closed. A separate inlet and
outlet (gas opening) of the container for purging and filling the
container with the process gas is also possible. In particular, the
gas opening of the container has a coupling unit for coupling the
container to a coupling unit of a process zone.
This gas opening can be used as a coupling unit and/or positioning
unit. The annealing takes place in a second process stage. For this
purpose, the container is conveyed out of the chamber into a
heating zone. After the annealing has ended, the multilayer body is
conveyed out of the heating zones into the cooling zones in order
for a further process stage to be carried out.
The conveying in the in-line process takes place, for example, by
passing a multiplicity of containers containing multilayer bodies
through the in-line installation in the form of a train. The entire
train is set in motion by the pushing action of one container. The
containers are moved simultaneously. This type of conveying is
known as a "pusher drive". In this case, the conveying
advantageously takes place in "indexing mode".
In a particular configuration, the apparatus is arranged in a
processing chamber which is selected from the group consisting of a
vacuum chamber, an atmospheric chamber and/or a high-pressure
chamber. An entire in-line installation may be integrated within
the processing chamber. By way of example, a heating or cooling
zone is accessible to the container containing the multilayer body
through a lock or is separated from a further process zone in the
processing chamber by such a lock. In particular, it is conceivable
for there to be a plurality of processing chambers, for example a
heating zone with a single-walled processing chamber, a cooling
zone with a double-walled chamber which is water-cooled. The
container is used to transport the multilayer body from processing
chamber to processing chamber.
In a particular configuration, the transparency body and/or the
energy transmitter and/or the container and/or the processing
chamber includes a material which is inert with respect to a
process gas. Moreover, it is advantageous for an entire annealing
process area to be inert with respect to the process gas used. The
process area also includes, for example, the energy source (primary
energy source).
The material is selected according to the process gas. By way of
example, glass, glass-ceramic and ceramic are conceivable. It is
also possible to use a fiber-reinforced material, such as
carbon-fiber-reinforced graphite. A material such as SiC, which has
a high coefficient of thermal conductivity, is also conceivable.
The container and/or the processing chamber may be completely or
partially made up of a metal or an alloy. A plastic which is
unaffected up to a defined temperature is also possible.
In addition to being chemically inert with respect to the process
gas, the following properties are also advantageous for the
material of the container: The material of the container is free
from distortion under the annealing conditions. Moreover, it is
able to withstand thermal shocks. This is the case in particular if
it has a low coefficient of thermal expansion. The thermal
softening point of the material of the container is above a maximum
temperature reached during the annealing. The container has a low
or defined permeability with respect to a process gas.
In a particular configuration, there is a device for detecting a
measurement of at least one physical parameter of the apparatus,
which is dependent on the annealing, for controlling the first and
second partial quantities of the quantity of energy.
A possible parameter is an absorption, transmission and/or
reflection property of a layer. The measurement of the parameter is
the value of the parameter. By way of example, a wavelength of an
absorption maximum may be dependent on the temperature. In this
case, the measurement of the parameter would be the corresponding
wavelength.
In particular, the parameter is a temperature of the multilayer
body. The measurement is in this case a value of the temperature.
Detection of the temperature of a layer of the multilayer body, of
the transparency body and/or of the container or of a wall of the
container is also conceivable. During the annealing, it is always
possible for at least one parameter of the multilayer body and/or
of a layer to be detected. By way of example, the partial quantity
of the quantity of energy which is taken up by the layer is
increased or reduced on the basis of the detected temperature of a
layer. In this way, temperature inhomogeneity or a temperature
gradient In the thickness direction of the multilayer body can be
avoided. However, if necessary, this temperature homogeneity can
also be increased.
By way of example, the device for detecting the temperature is a
pyrometer which is directed onto the layer. By way of example, the
pyrometer detects the thermal radiation which is emitted by the
layer. The temperature of the layer can be established on the basis
of the thermal radiation. A temperature detector which is connected
to the layer and the temperature of which is controlled by heat
conduction is also conceivable.
It is also conceivable for the temperature of the layer or of the
multilayer body to be measured not directly but rather indirectly.
By way of example, a pyrometer is directed onto the container in
which the multilayer body is being annealed. The temperature of the
container may be influenced by the temperature of the multilayer
body. The temperature of the layer of the multilayer body can be
worked out from the temperature of the container. The quantity of
energy or the partial quantity of the quantity of energy is
controlled on the basis of the measured container temperature. For
this purpose, for example prior to the annealing, a type of
"calibration measurement" is to be carried out, representing a
relationship between the measured temperature of the container and
the actual temperature of the layer or of the layer body. The
"calibration measurement" indicates a desired value for the
temperature. The actual value is detected. A comparison between
desired value and actual value supplies a control variable for
controlling the quantities of energy.
The detection (and also the control of the partial quantities of
the quantity of energy) takes place in particular with a local
resolution in the thickness direction of the multilayer body and
with a temporal resolution within the time frame of the annealing.
By way of example, the multilayer body is heated at an annealing
rate of 25.degree. C./s. Then, both the detection and the control
of the partial quantities of the quantity of energy would take
place so quickly that a temperature difference between the layers
of the multilayer body during annealing remains, for example, below
a prescribed maximum.
The temperature inhomogeneity in the thickness direction may, in
combination with a transient deformation of the multilayer body,
also lead to a lateral temperature inhomogeneity in the multilayer
body. Lateral means, for example, within a layer of the multilayer
body perpendicular to the thickness direction. As described in the
introduction, the multilayer body, during the annealing, rests, for
example, on a base made from graphite. The supply or uptake of the
quantity of energy by the layer of the multilayer body which rests
on the base takes place through heat conduction. Transient
deformation of the multilayer body in the form of bending of the
multilayer body may occur as a result of temperature inhomogeneity
in the thickness direction. In the process, the contact between the
multilayer body and the base of the container which is required for
the heat conduction is partially detached. This leads to a lateral
temperature inhomogeneity of the resting layer or of the multilayer
body. Therefore, it is particularly advantageous if there is a
local resolution not only in the thickness direction but also
laterally, in order for the parameter to be detected (and the
quantities of energy to be controlled).
In one particular configuration, the parameter is a deformation of
the multilayer body. Deformation may occur as a result of a
temperature inhomogeneity being present. By way of example, the
multilayer body is curved concavely. The multilayer body rests on
the base of, for example, a container. Concave deformation results
in a distance between the bearing surface and the multilayer body
forming in the edge region of the multilayer body. A measurement of
a deformation of this type can be detected, for example, using a
laser interferometry or laser light reflection device. The
quantities of energy are controlled on the basis of the
measurement. It is advantageous if the measurement is recognized
during an early stage of the deformation and can be reacted to
quickly.
For an abovementioned device for detecting a measurement of a
parameter which is dependent on the annealing with the aid of an
optical device (e.g. laser), it is advantageous if the layer which
is to be examined is accessible to light from the optical device
and a detection signal can be unambiguously assigned to the
parameter which Is to be detected. The wavelength of a laser
should, for example, differ sufficiently from the thermal radiation
of the multilayer body. If the apparatus is equipped with a
container, it would be advantageous if the transparency body is
sufficiently transparent to the light of the laser.
With the aid of the apparatus, it is also possible to achieve a
desired deformation of the multilayer body. For this purpose, it
may also be appropriate to monitor the deformation during the
annealing in the manner described above. By way of example, it is
possible to produce a curved thin-film solar cell. To achieve
controlled deformation, by way of example the multilayer body is
laid onto a corresponding mold or mask. The mold or mask may itself
be an energy source. The multilayer body is heated to above a
softening point of the substrate layer. As a result, the multilayer
body adopts a shape which corresponds to that of the mask or of the
mold. The mask is, for example, integrated in a base of the
container. The mask could, for example, be the transparency
body.
A second aspect of the invention provides a process for annealing a
multilayer body which has a first layer and at least one second
layer, through uptake of a quantity of energy by the multilayer
body involving uptake of a first partial quantity of the quantity
of energy by the first layer and uptake of a second partial
quantity of the quantity of energy by the second layer, at least
one energy source being used to supply the quantity of energy to
the multilayer body. In this process, in particular an apparatus as
described above is used. The process steps comprise: arranging the
multilayer body between a first energy source and at least one
second energy source, so that the first layer is arranged between
the first energy source and the second layer, and the second layer
is arranged between the second energy source and the first layer,
the energy source used being at least one energy source for
providing a defined electromagnetic radiation with a radiation
field, and at least one of the layers absorbing the electromagnetic
radiation and being arranged in the radiation field of the energy
source, and arranging a transparency body in the radiation field of
the energy source between the energy source and the layer which
lies in the radiation field of the energy source and absorbs the
defined electromagnetic radiation, and annealing the multilayer
body.
In a particular configuration, the transparency body absorbs a
certain quantity of energy and supplies the quantity of energy to
the layer. This takes place in particular through heat conduction
and/or heat radiation from the transparency body to the layer.
In a particular configuration, at least one layer is brought into
contact with a process gas. This takes place before, during and/or
after the annealing. It is possible for not just one layer, but the
entire multilayer body to be brought into contact with the process
gas.
In a further configuration, detection of a measurement, which is
dependent on the annealing, of a physical parameter of the
multilayer body is carried out during the annealing, in order to
control the uptake of the quantity of energy during the annealing
and to control the first and second partial quantities of the
quantity of energy. In a particular configuration, the transparency
body supplies the quantity of energy the layer by heat conduction
and/or heat radiation.
In a particular configuration, the process is carried out as a
process stage in an in-line process and/or a quasi-in-line process
comprising at least two process stages. Each of the process stages
is carried out at a separate location (process zone). In
particular, the above-described apparatus with the container is
used to transport the multilayer body from process zone to process
zone. The process stages may, for example, be heating zones or
cooling zones, which may be equipped with coupling units in order
for the vessels to be filled with gas or emptied. The process
stages may be connected to one another by a surrounding processing
chamber. The surrounding enclosure may, for example, be a vacuum
chamber, an atmospheric pressure chamber or a high-pressure
chamber. Furthermore, the process stages may be provided, at the
inlet and outlet, with vacuum or high-pressure locks for the
material being processed.
A further aspect of the invention provides a multilayer body,
having a first layer comprising at least one substance selected
from the group consisting of copper, indium, gallium, sulfur and/or
selenium, and a second layer comprising glass, a lateral diameter
of the multilayer body being selected from the range between 0.3 m
and 5 m. The diameter is preferably over 1.0 m up to 5 m.
In a particular configuration, the multilayer body is produced by
the process described above. At least one substance in the first
layer of the multilayer body is selected from the group consisting
of copper, indium, gallium, sulfur and selenium, and a second layer
comprising glass is used. The lateral diameter (dimension) of the
multilayer body is selected from the range between 0.3 m and 5 m.
The layer is, for example, a copper/indium selenide semiconductor
layer.
The multilayer body described is, for example, a thin-film solar
cell or a thin-film solar module, which comprises a multiplicity of
individual thin-film solar cells connected in series. The glass is
preferably soda-lime glass. The corresponding layer functions as a
substrate layer. A molybdenum layer is applied to the substrate
layer as an electrode, and a functional layer, namely a
copper/indium/gallium/sulfo-selenide (CIGSSe) semiconductor layer,
is applied on top of the molybdenum layer. A thickness of the layer
body, comprising glass body and semiconductor layer, is typically 2
to 4 mm, with a molybdenum layer of approx. 0.5 .mu.m and a
semiconductor layer of approx. 3 .mu.m. The range given for the
thickness of the multilayer body is not exclusive. The limiting
factor is the ability to produce a large-substrate which is as
planar as possible and therefore can be processed using the
apparatus described or using the process described in order to
produce a multilayer body.
To summarize, the invention results in the following advantages: A
large-area multilayer body with an asymmetric layer structure (e.g.
multilayer body with a single layer on a substrate layer) using a
high annealing rate of over 1.degree. C./s is possible. The layers
of the multilayer body may have a greatly varying coefficient of
thermal conductivity. Annealing takes place particularly reliably
through temporal and local resolution of the detection and of the
control of a measurement of a parameter which is dependent on the
annealing. Annealing is possible up to almost a softening point of
a substrate layer. Permanent deformation of the multilayer body is
possible when annealing at over the softening point of the
substrate layer. The use of a container allows a defined annealing
environment with a defined process-gas atmosphere to be created. In
particular, a toxic and/or corrosive process gas can be used. The
process can be carried out in an in-line installation with a high
throughput.
An apparatus for annealing a multilayer body and a corresponding
process are presented on the basis of an exemplary embodiment and
the associated figures. The figures are diagrammatic and not to
scale.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross section through an apparatus for annealing a
multilayer body, as seen from the side.
FIG. 2 shows a cross section through an apparatus for annealing
having a container in which the multilayer body is arranged.
FIG. 3 shows a cross section through an annealing apparatus having
a container in which the multilayer body and an energy transmitter
are arranged.
FIG. 4 shows part of a transparency body.
FIGS. 5a and 5b show a device for detecting the measurement of a
deformation of the multilayer body.
FIG. 6 shows a flowchart representing a process for annealing a
multilayer body.
FIG. 7 shows an apparatus for annealing a multilayer body, which is
arranged in a processing chamber.
FIGS. 8a and 8b each show an in-line process.
FIGS. 9a and 9b show a container with coupling unit in the
processing mode and in the conveying mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the exemplary embodiments, a thin-film solar module 1 is being
produced. The thin-film solar module has a basic surface area of
850.times.600 mm.sup.2. The thickness of the solar module is 3 mm,
a 0.5 .mu.m thick layer of molybdenum 3 and a 0.5 .mu.m thick
copper/indium/gallium/sulfo-selenide (CIGSSe) semiconductor layer 4
being produced on a substrate layer comprising soda-lime glass
2.
Before the annealing, the multilayer body 1 has the following layer
structure: soda-lime
glass/molybdenum/copper(gallium)/indium/selenium. Soda-lime glass
functions as a substrate layer 2 for the molybdenum layer 3 and the
multiple layer 4. Gallium is incorporated in the copper layer. A
gas mixture comprising hydrogen sulfide, helium and hydrogen is
used as process gas 16. Gaseous selenium or hydrogen selenide is
formed during the annealing.
According to a first embodiment, the multilayer body is placed onto
a transparency body 5 made from glass-ceramic (FIG. 1). The
transparency body has a multiplicity of spacers 6 made from the
same material as that which forms the transparency body 5 (FIG. 4).
The transparency body 5 is situated between the substrate layer 2
of the thin-film solar module or its starting form 1 and an energy
source 7. The energy source 7 comprises a plurality of arrays of
halogen lamps arranged adjacent to one another to form a matrix.
The matrix supplies a homogeneous radiation field 8. The
transparency body 5 is situated in the radiation field 8 of the
energy source 7. It absorbs some of the electromagnetic radiation 9
from the energy source and transmits the quantity of energy
absorbed to the substrate layer 2 through heat conduction 10. The
glass layer 2 is annealed primarily through the heat conduction
10.
A second transparency body 12 comprising glass-ceramic is arranged
between a second energy source 11 and the selenium layer (outermost
coating of the layer 4). The second energy source 11 is designed,
just like the first energy source 7, as a matrix. The second
transparency body 12 absorbs some of the electromagnetic radiation
13 from the second energy source 11. Some of the quantity of energy
which is taken up in the process is released to the multiple layer
4 in the form of heat radiation 14. The transparency body 12 also
transmits electromagnetic radiation 13, so that this radiation
impinges on the multiple layer 4. The multiple layer 4 lies in the
radiation field 15 of the energy source 11. The multiple layer 4 is
annealed primarily through heat radiation 14.
The multilayer body 1 is arranged in a container 17 in the manner
described above (FIG. 2). The cover 18 and the base 19 are formed
by the transparency bodies 5 and 12. A side wall 20 of the
container 17 consists of carbon fiber-reinforced carbon (CFC).
As set forth in FIG. 6, after the multilayer body has been laid on
the baseplate at step 61, the container is filled with the process
gas and closed. The annealing then takes place at step 62 at an
annealing rate of 5.degree. C./s, the energy source 7 and 11 being
controlled separately.
A further exemplary embodiment is distinguished by the fact that an
energy transmitter 26 is integrated in the box (FIG. 3).
The following control circuit is used for the energy source 7: a
lateral actual temperature profile of the transparency body 5 is
measured using a pyrometer in the form of an infrared sensor of
suitable wavelength. The contact with the multilayer body means
that the temperature profile of the substrate layer 2 can be
determined from the temperature profile of the transparency body by
means of calibration. A control signal, which is used to control
the radiation output of the energy source 7, is determined by a
control algorithm via actual and desired values of the temperature
of the transparency body.
A control variable for a control circuit for controlling the energy
source 11 is a transient bending 21 of the substrate layer 2. The
bending 21 is measured by laser interferometry on the substrate
side 22 or layer side 23. Measurement points are the substrate
center 24 and a corner 25 of the multilayer body. During the laser
interferometry, the change in distance caused by bending is
measured and is used to determine the control signal for the
associated energy source.
In a further exemplary embodiment, the control variable for the
energy source 11 is the temperature of the transparency body
12.
A further exemplary embodiment is indicated in FIG. 7. The
container 17 has gas openings in the form of a gas inlet 31 and a
gas outlet 32. These openings have, for example, a closeable valve
which is closed after the gas exchange has ended. While the
container 17 containing the multilayer body 1 is being conveyed to
the next process zone, the valve remains closed. One of the process
zones is a heating zone. The heating zone comprises two arrays of
halogen lamps. The annealing apparatus is produced as a result of
the container (with transparency body) being conveyed into the
heating zone between the two arrays.
A further exemplary embodiment is likewise indicated in FIG. 7. In
this case, the entire apparatus is in a processing chamber 30,
which can be evacuated and filled with a specific gas.
FIGS. 8a and 8b illustrate the principle of an in-line process
using an in-line installation. In a first embodiment, the entire
in-line installation is arranged in the processing chamber 30 (FIG.
8a). The multilayer body 1 in the container 17 is conveyed 36 from
process zone 33 to process zone 34. A different process stage is
carried out at each of the process zones. In process zone 33, the
container 17 is filled with the process gas and heated. In process
zone 34, the container 17 is evacuated and cooled. Alternatively,
each of the process zones 33 and 34 is arranged in a dedicated,
separate process chamber 301 to 304 (FIG. 8b). The in-line
installation is divided between a plurality of process chambers.
The process chambers are provided with locks, through which the
containers pass into the process chambers.
FIGS. 9a and 9b show how an arrangement for annealing or
processing, including coupling unit, may be designed. FIG. 9a shows
a cross section through the container 17 in processing mode. The
container 17 has a cover 18 in the form of a transparency body 12.
The base 19 consists of highly absorbent material. In one
embodiment, the material is graphite. A side wall 20 of the
container 17 is a frame of the container 17 made from CFC. Gas
inlet 31 and gas outlet 32 are integrated in the side wall of the
container. Self-closing valves 40 are likewise integrated in the
side wall 20. These valves can be used to open and close the gas
openings 31 and 32 for evacuating the container or filling the
container with a gas.
A coupling unit 42 of the container of the process zone 33 is
likewise integrated in the side wall. The coupling unit 42 may, for
example, be designed as a conical opening. This opening is used to
plug-connect the container 17 to a coupling unit 41, which is
formed inversely with respect to the opening, of the process zones.
Gas lines 43 are integrated in the coupling units 41 and 42. When
the container has in this way been arranged with, for example, the
process zone 33, by way of example any desired process gas can be
introduced or discharged during this process stage, or the
processing vessel can be evacuated and purged with inert gas. In
the form illustrated, the coupling units 42 of the container 17 and
of the process zone 33 are used to produce a process-gas
atmosphere.
After the processing or annealing has ended, the coupling unit is
pulled off and the valves 40 close automatically. Then, in
conveying mode, the container can be conveyed to the next process
zone 34. The zone 34 may, for example, be provided with a further
coupling unit, which, for example, tops up consumed processing gas
or introduces a new processing gas.
* * * * *